In situational awareness systems, it is desirable to maintain consistent periodic communication with one or more mobile entities. Such consistent communications are useful in situations have a risk of incapacitation of the mobile entity, such as battlefield applications, recreational activities in rugged environments, or civilian search and rescue operations. If the periodic communications from the mobile entities cease, a search can be carried out at the last reported location. A variation on this theme could include an automated communications unit that periodically broadcasts a signal to other communication units, such that the signal itself can be employed to locate the mobile entity. However, most situational awareness systems only determine the presence of a user's most recent reported location. Therefore, an estimate of the location of the user needs to be made based on other known previously reported information. Additionally, the real-time condition of the mobile entity is unknown and assumptions need to be made based on other known previously reported information.